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1.
Adv Mater ; 36(18): e2311022, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38290153

RESUMEN

2D van der Waals (vdW) ferromagnetic crystals are a promising platform for innovative spintronic devices based on magnetic skyrmions, thanks to their high flexibility and atomic thickness stability. However, room-temperature skyrmion-hosting vdW materials are scarce, which poses a challenge for practical applications. In this study, a chemical vapor transport (CVT) approach is employed to synthesize Fe3GaTe2 crystals and room-temperature Néel skyrmions are observed in Fe3GaTe2 nanoflakes above 58 nm in thickness through in situ Lorentz transmission electron microscopy (L-TEM). Upon an optimized field cooling procedure, zero-field hexagonal skyrmion lattices are successfully generated in nanoflakes with an extended thickness range (30-180 nm). Significantly, these skyrmion lattices remain stable up to 355 K, setting a new record for the highest temperature at which skyrmions can be hosted. The research establishes Fe3GaTe2 as an emerging above-room-temperature skyrmion-hosting vdW material, holding great promise for future spintronics.

2.
Clin Lab ; 69(5)2023 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-37145087

RESUMEN

BACKGROUND: Acute myeloid leukemia (AML) is a hematologic malignancy characterized by the abnormal proliferation of myeloid hematopoietic cells and it is urgently needed to develop new molecular biomarkers to predict clinical outcomes and improve therapeutic effects. METHODS: The differentially expressed genes were identified by comparing TCGA with GETx data. Univariate LASSO and multivariate cox regression analysis were performed to identify prognosis-associated pseudogenes. Based on the overall survival of related pseudogenes, we used them to construct a prognostic model for AML patients. Moreover, we built the pseudogenes-miRNA-mRNA ceRNA networks and explored their involved biological functions and pathways via GO and KEGG enrichment analysis. RESULTS: Seven prognosis-associated pseudogenes were identified, including CCDC150P1, DPY19L1P1, FTH1P8, GTF2IP4, HLA-K, NAPSB, and PDCD6IPP2. The risk model based on these 7 pseudogenes could accurately predict the 1-year, 3-year, and 5-year survival rates. The GO and KEGG enrichment analyses demonstrated that these prognosis-associated pseudogenes were significantly enriched in cell cycle, myeloid leukocyte differentiation, regulation of hemopoiesis, and other critical cancer-related biological functions and pathways. We systematically and comprehensively analyzed the prognostic role of pseudogenes in AML. CONCLUSIONS: The prognostic model of pseudogenes we identified is an independent predictor of overall survival in AML and could be used as biomarker for AML treatment.


Asunto(s)
Leucemia Mieloide Aguda , MicroARNs , Humanos , Pronóstico , Seudogenes/genética , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/genética , Ciclo Celular
3.
Phytomedicine ; 116: 154870, 2023 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-37207387

RESUMEN

BACKGROUND: Sanguisorba saponin extract (SSE) is the main active part of Sanguisorba officinalis with various pharmacological activities such as anti-inflammatory, anti-bacterial and anti-oxidant. However, its therapeutic role and underlying mechanisms for ulcerative colitis (UC) still need to be elucidated. PURPOSE: This study aims to explore the therapeutic effect, effectiveness-material basis-quality markers (Q-markers) and prospective mechanism of function of SSE on UC. METHODS: Fresh 2.5% dextran sulfate sodium salt (DSS) solution was placed in drinking bottles for 7 days to induce a mouse model of UC. SSE and sulfasalazine (SASP) were supplemented to mice by gavage for consecutive 7 days to investigate the therapeutic role of SSE on UC. Mouse monocyte macrophages (RAW264.7) and human normal colonic epithelial (NCM460) cells were treated with LPS to induce inflammatory responses, followed by pharmacodynamic examination with different concentrations of SSE. Hematoxylin-eosin (HE) and Alcian blue staining were conducted to evaluate the pathological damage of mice colon. Lipidomic technology was conducted to explore the differential lipids closely related to the disease process of UC. Quantitative PCR analysis, immunohistochemistry and ELISA kit were used to measure the expression levels of the corresponding proteins and pro-inflammatory factors. RESULTS: SSE treatment could effectively reduce the elevated expressions of pro-inflammatory factors in RAW264.7 and NCM460 cells due to LPS stimulation. Intragastric administration of SSE was found to significantly alleviate the symptoms of DSS-induced colon injury and low-polar saponins in SSE. Low polarity saponins, especially ZYS-II, were proved to be the main active substances of SSE in treating UC. In addition, SSE could significantly ameliorate the aberrant lipid metabolism in UC mice. The role of phosphatidylcholine (PC)34:1 in the UC pathogenesis has been fully verified in our previous studies. Herein, SSE-dosing effectively reversed the metabolic disorder of PCs in UC mice, and increased the PC34:1 level to normal via up-regulating the expression of phosphocholine cytidylyltransferase (PCYT1α). CONCLUSION: Our data innovatively revealed that SSE could significantly alleviate the symptoms of UC by reversing the disorder of PC metabolism induced by DSS modeling. SSE was proved for the first time to be a promising and effective candidate for UC treatment.


Asunto(s)
Colitis Ulcerosa , Colitis , Sanguisorba , Saponinas , Humanos , Animales , Ratones , Colitis Ulcerosa/inducido químicamente , Colitis Ulcerosa/tratamiento farmacológico , Colitis Ulcerosa/patología , Saponinas/efectos adversos , Lipopolisacáridos/farmacología , Metabolismo de los Lípidos , Colon/patología , Sulfato de Dextran/efectos adversos , Modelos Animales de Enfermedad , Ratones Endogámicos C57BL , Colitis/patología
4.
Appl Biochem Biotechnol ; 195(11): 6633-6652, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36897493

RESUMEN

In this study, we aimed to explore long non-coding RNA (lncRNA) sustained low-efficiency dialysis (SLED1) correlated with Bcl-2 apoptosis pathway in acute myeloid leukemia (AML). This study further aimed to determine its role in the regulation of AML progression and its action as a potential biomarker for better prognosis. AML microarray profiles GSE97485 and probe annotation from the Gene Expression Omnibus (GEO) database from the National Center for Biotechnology Information (NCBI) were detected using the GEO2R tool ( http://www.ncbi.nlm.nih.gov/geo/geo2r/ ). The expression of AML was downloaded from the TCGA database ( http://cancergenome.nih.gov/ ). The statistical analysis of the database was processed with R software. Bioinformatic analysis found that lncRNA SLED1 is highly expressed in AML patients and is associated with poor prognosis. We found that the increased SLED1 expression levels in AML were significantly correlated with FAB classification, human race, and age. Our study has shown that upregulation of SLED1 promoted AML cell proliferation and inhibited cell apoptosis in vitro; RNA sequencing showed increased expression of BCL-2 and indicated that SLED1 might promote the development of AML by regulating BCL-2. Our results showed that SLED1 could promote the proliferation and inhibit the apoptosis of AML cells. SLED1 might promote the development of AML by regulating BCL-2, but the mechanism involved in the progression of AML is unclear. SLED1 plays an important role in AML progression, may be applied as a rapid and economical AML prognostic indicator to predict the survival of AML patients, and help guide experiments for potential clinical drag targets.


Asunto(s)
Terapia de Reemplazo Renal Híbrido , Leucemia Mieloide Aguda , ARN Largo no Codificante , Humanos , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Línea Celular Tumoral , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Proliferación Celular/genética , Pronóstico , Apoptosis/genética , Proteínas Proto-Oncogénicas c-bcl-2
5.
Clin Exp Med ; 23(6): 2639-2649, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36645547

RESUMEN

Acute myeloid leukemia (AML) is a malignancy of the stem cell precursors of the myeloid lineage. DNA methylation is an important DNA modification that regulates gene expression. Investigating AML heterogeneity based on DNA methylation could be clinically informative for improving clinical diagnosis and prognosis. The AML subtypes based on DNA methylation were identified by unsupervised consensus clustering. The association of these subtypes with gene mutation, copy number variations, immune infiltration and clinical features were further explored. Finally, univariate, LASSO and multivariate cox regression analyses were used to identify prognosis-associated genes and construct risk model for AML patients. In addition, we validated this model by using other datasets and explored the involved biological functions and pathways of its related genes. Three CpG island methylator phenotypes (CIMP-H, CIMP-M and CIMP-L) were identified using the 91 differential CpG sites. Overall survival, morphology, macrophages M0 and monocytes were distinct from each other. The most frequently mutated gene in CIMP-L was DNMT3A while which in CIMP-M that was RUNX1. In addition, the TIDE scores, used to predict the response to immune checkpoint inhibitors, were significantly different among CIMPs. The CIMP-associated prognosis risk model (CPM) using 32 key genes had convinced accuracy of prediction to forecast 0.5-year, 1-year, 3-year and 5-year survival rates. Moreover, the risk score-related genes were significantly enriched in pattern specification process, regionalization, embryonic organ morphogenesis and other critical cancer-related biological functions. We systematically and comprehensively analyzed the DNA methylation in AML. The risk model we constructed is an independent predictor of overall survival in AML and could be used as prognostic factor for AML treatment.


Asunto(s)
Metilación de ADN , Leucemia Mieloide Aguda , Humanos , Variaciones en el Número de Copia de ADN , Pronóstico , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/genética , Islas de CpG
6.
J Pharm Biomed Anal ; 223: 115130, 2023 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-36335849

RESUMEN

Zhi-Zi-Chi decoction (ZZCD), comprising of Gardenia jasminoides Ellis (GJE) and Semen sojae preparatum (SSP), is a classical Chinese medicine formula. A novel analysis strategy was set up to obtain an evaluation of ZZCD on attenuation and synergy of compatibility. High-resolution ion trap/time-of-flight mass spectrometry (LC-IT-TOF-MS) was used for qualitative analysis. Variant ingredients were analyzed to compare the componential differences between ZZCD formula and single herbs. Based on our previous fingerprint studies that combined with chemometric methods, 13 remarkable chemical markers were selected and evaluated for quantitative determination by high performance liquid chromatography (HPLC) in three different ratios of ZZCD. 62 compounds in ZZCD, 55 compounds in GJE and 16 compounds in SSP were characterized. The compatibility of GJE and SSP may lead to the undetection of hepatotoxic components such as genipin and the emergence of protective components such as jasminoside A, which was not found in single herbs. Meanwhile, 13 selected chemical markers were successfully determined in three ratios of ZZCD. The compatibility may lead to the decrease of toxic ingredients and the increase of beneficial ingredients. By comparing the dissolution of chemical markers, iridoids in GJE and flavonoids in SSP had the best dissolution when the compatibility ratio was 1:1. This strategy would be a valuable reference for further study on the compatibility of traditional Chinese medicine formula.


Asunto(s)
Medicamentos Herbarios Chinos , Gardenia , Medicamentos Herbarios Chinos/química , Cromatografía Líquida de Alta Presión/métodos , Medicina Tradicional China , Gardenia/química , China
7.
Materials (Basel) ; 15(3)2022 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-35161002

RESUMEN

Rotating backward extrusion (RBE) is one of severe plastic deformation (SPD) methods used to produce cylindrical components with a very large strain by a single pass. In this study, the microstructure and texture evolution in the different regions of Mg-12Gd-4Y-2Zn-0.5Zr (wt.%) alloys via RBE process were investigated by using optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron back-scatter diffraction (EBSD). The results showed that the cup-shaped sample formed by RBE process exhibited typical gradient microstructure expanding from its inner wall to outer wall along the radial direction (RD). The average grain size of the RBEed sample decreased when the radius decreased from the edge region to the center region along the RD, which was attributed to the different strains and strain rates in the different regions. It also could be observed that the center region showed highest deformation and the edge region exhibited the lowest deformation in the RBEed sample along the RD. In addition, the grain refinement mechanisms of the experimental alloy containing long-period stacking ordered (LPSO) phases after RBE with 100 N were continuous dynamic recrystallization (CDRX), discontinuous dynamic recrystallization (DDRX) and particle stimulated nucleation (PSN).

8.
J Sep Sci ; 43(14): 2880-2888, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32388927

RESUMEN

In this study, a solid-phase extraction with liquid chromatography and tandem mass spectrometry method was developed to determine the degree of glycosylation of glycosylation sites and the ratio of free carrier protein to total carrier protein for glycoconjugate vaccines. To remove and enrich the glycosylated peptides, a solid-phase extraction method was developed, optimized, and hyphenated to liquid chromatography-tandem mass spectrometry. The developed solid-phase extraction with liquid chromatography-tandem mass spectrometry method was shown to possess a wide linear dynamic range (0.03-100 µg/mL), a high sensitivity (0.03 µg/mL for CRM197), good interday and intra-day precision (relative standard deviation of peak area < 3.3%), and good recoveries from vaccine matrix (90-105%). Finally, the method was utilized to determine the degree of glycosylation and free carrier protein to total carrier protein ratio for pneumococcal conjugate vaccines and meningococcal vaccines. For quality evaluation of glycoconjugate vaccines, the method could provide more information than the traditional size exclusion chromatography method. Fourteen and twelve reported glycosylation sites for CRM197- and tetanus toxin-based vaccines can be detected, respectively.


Asunto(s)
Glicoconjugados/análisis , Vacunas/análisis , Cromatografía Liquida , Glicoconjugados/metabolismo , Glicosilación , Extracción en Fase Sólida , Espectrometría de Masas en Tándem , Vacunas/metabolismo
9.
Platelets ; 31(1): 55-61, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-30744465

RESUMEN

Immune thrombocytopenia (ITP) is an autoimmune disease with a mild to severe risk of bleeding complications. First line treatment includes corticosteroids, immunoglobulins, or other. In this large cohort study, first-line strategies for treatment-naive adult primary ITP was studied in a real-world setting. Records from all adult ITP patients who received first-line treatment between January 2010 and December 2017 at Qilu Hospital were reviewed retrospectively (n = 699). During the study period, 271 patients were treated with high-dose dexamethasone (HDD) and 289 patients were treated with conventional prednisone (alone or in combination with other drugs). Initial responses were similar for the two groups (88.56% vs. 86.51%, P = 0.462), but patients in the HDD group responded earlier than the prednisone group (3 days vs. 5 days, P < 0.001). The sustained response (SR) at 6 months was lower in the HDD group than in the prednisone group (35.4% vs. 47.1%, P = 0.040). However, the SR at 12 months and at the end of our follow-up were not significantly different between the groups. Overall duration of response (DOR) in the prednisone group was longer than in the HDD group throughout the follow-up period (P = 0.007). However, the incidence of SR and overall DOR were not significantly different between the HDD group and the prednisone 3 months group (prednisone terminated within 3 months). The presence of anti-GPIb-IX autoantibodies was a predictive factor for a poor initial response to corticosteroids therapy (P < 0.05). However, neither of the two antiplatelet autoantibodies were correlated with the opportunity to achieve SR and overall DOR in both groups throughout the follow-up period (P > 0.05). Adverse events were more frequent and long-lasting in the prednisone group. Our study showed that HDD provided an effective and more rapid response as initial treatment of ITP, with comparable long-term prognosis and better tolerance when compared with conventional PDN (less than 3 months) in the real-world setting.


Asunto(s)
Dexametasona/uso terapéutico , Inmunosupresores/uso terapéutico , Púrpura Trombocitopénica Idiopática/tratamiento farmacológico , Adulto , Autoanticuerpos/inmunología , Plaquetas/inmunología , Plaquetas/metabolismo , Dexametasona/administración & dosificación , Dexametasona/efectos adversos , Femenino , Humanos , Inmunosupresores/administración & dosificación , Inmunosupresores/efectos adversos , Incidencia , Estimación de Kaplan-Meier , Persona de Mediana Edad , Púrpura Trombocitopénica Idiopática/diagnóstico , Púrpura Trombocitopénica Idiopática/mortalidad
10.
J Sep Sci ; 42(14): 2444-2454, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31087615

RESUMEN

An online supercritical fluid extraction with supercritical fluid chromatography system could provide sequential extraction and quantitative analysis of lignans in Schisandra chinensis. Supercritical fluid extraction conditions were optimized at 15 MPa, 50°C, and 4 min with supercritical CO2 adding 1% methanol; the elution volume and flow rate were set at 6 mL and 2 mL/min to blow extract out of the tank completely. The split-flow rate was confirmed at 2.5%, which determines injection volume and accuracy of quantitative detection. The factors having negative influences on supercritical fluid chromatography retention in the online system, including sample loading forms and backpressure settings, are discussed in the paper. At last, an extraction-quantitative method for lignans in Schisandra chinensis was developed, which could be finished within 19.5 min. The total content percentage of four lignans (Schisandrin, Schisandrin A, Schisandrin B and Schisandrol B) in four batches was respectively measured to be 1.42, 1.54, 1.62, and 1.90%.


Asunto(s)
Lignanos/análisis , Extractos Vegetales/química , Schisandra/química , Cromatografía con Fluido Supercrítico
11.
J Pharm Biomed Anal ; 161: 444-454, 2018 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-30216793

RESUMEN

The isoflavones widely exist in the daily diets and interferences are usually inevitable in the determination of the in vivo level of the same analytes. A new strategy to eliminate the dietary interference was established to evaluate the exposure of isoflavones including daidzin, glycitin, genistin, daidzein, glycitein, and genistein in rats fed with Semen Sojae Praeparatum (SSP) extract. Plasma samples were pretreated by liquid-liquid extraction with ethyl acetate using quercetin as the internal standard (IS). The chromatographic separation was achieved on a Symmetry C18 column (100 mm × 3.0 mm) using a gradient mobile phase consisting of acetonitril and water (containing 0.1% formic acid) with a run time of 13.0 min at a flow rate of 0.4ml/min. The detection was carried out by a triple-quadrupole tandem mass spectrometer in multiple reaction monitoring (MRM) mode via polarity switching between negative (for and positive (for daidzin glycitin) ionization mode. All calibration curves exhibited good linearity (r> 0.99) over a wide concentration range for all components. The lower limit of quantitation (LLOQ) was in the range of 0.1-0.4 ng/ml. The intra-day and inter-day precisions (RSD) at three different levels were both less than 14.9% and the accuracies (RE) ranged from -9.3% to 14.5%. The extraction recoveries of the analytes and the IS ranged from 85.7% to 100.2%. The validated method was first successfully applied to pharmacokinetic study of the six isoflavones in rat plasma after oral administration of SSP extract. The dynamic baseline levels of six isoflavones in blank plasma from rats consuming food containing dietary isoflavones were measured for the correction of the plasma concentrations. The principle pharmacokinetic parameters were calculated from rats with or without regular commercial food, and found to be altered by the dietary food containing some isoflavones.


Asunto(s)
Medicamentos Herbarios Chinos/farmacocinética , Glycine max/química , Isoflavonas/farmacocinética , Animales , Cromatografía Liquida , Medicamentos Herbarios Chinos/química , Interacciones Alimento-Droga , Isoflavonas/sangre , Límite de Detección , Extracción Líquido-Líquido , Masculino , Ratas , Espectrometría de Masas en Tándem
12.
Sci Total Environ ; 640-641: 973-980, 2018 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-30021330

RESUMEN

Fe(II) activated sodium percarbonate (SPC) process (SPC/Fe(II)) could efficiently remove sulfamethoxazole (SMX) in the aqueous phase, and has the potential in groundwater remediation. However, the degradation mechanisms, especially the degradation products and pathways till now have remained unclear. In the present study, intermediate products were identified using high resolution liquid chromatography coupled with ion trap and time-of-flight mass spectrometry (LCMS-IT-TOF). Nine intermediate products were identified, six of which have not yet been reported during the oxidation of SMX. The oxidation mechanisms involved hydroxyl substitution, the cleavage of sulfonamide bond, isoxazole ring opening and a rearrangement following the loss of the SO2-group. Based on the identified intermediate products, the degradation pathways of SMX by SPC/Fe(II) process were illustrated. Fenton's reaction after the dissolution of SPC was proposed as the main reaction mechanisms, which was checked and confirmed by radical species detection tests and radical species scavenging studies. The results showed that although both O2- and HO were present in SPC/Fe(II) system, HO was dominant in the system while O2- was seldom involved in the degradation of SMX. These findings provided useful information and supported the application of this advanced oxidation process for antibiotics elimination in the groundwater.

13.
Food Chem ; 258: 189-198, 2018 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-29655722

RESUMEN

Semen sojae praeparatum with homology of medicine and food is a famous traditional Chinese medicine. A simple and effective quality fingerprint analysis, coupled with chemometrics methods, was developed for quality assessment of Semen sojae praeparatum. First, similarity analysis (SA) and hierarchical clusting analysis (HCA) were applied to select the qualitative markers, which obviously influence the quality of Semen sojae praeparatum. 21 chemicals were selected and characterized by high resolution ion trap/time-of-flight mass spectrometry (LC-IT-TOF-MS). Subsequently, principal components analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were conducted to select the quantitative markers of Semen sojae praeparatum samples from different origins. Moreover, 11 compounds with statistical significance were determined quantitatively, which provided an accurate and informative data for quality evaluation. This study proposes a new strategy for "statistic analysis-based fingerprint establishment", which would be a valuable reference for further study.


Asunto(s)
Medicamentos Herbarios Chinos/análisis , Medicamentos Herbarios Chinos/química , Espectrometría de Masas/estadística & datos numéricos , Biomarcadores Farmacológicos/análisis , Cromatografía Líquida de Alta Presión , Análisis Discriminante , Análisis de los Mínimos Cuadrados , Espectrometría de Masas/métodos , Análisis de Componente Principal , Control de Calidad , Glycine max/química
14.
Environ Sci Pollut Res Int ; 20(6): 3649-56, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23128991

RESUMEN

The Fenton-like degradation of nalidixic acid was studied in this work. The effects of Fe(3+) concentration and initial H(2)O(2) concentration were investigated. Increasing the initial H(2)O(2) concentration enhances the degradation and mineralization efficiency for nalidixic acid, while Fe(3+) shows an optimal concentration of 0.25 mM. A complete removal of nalidixic acid and a TOC removal of 28 % were achieved in 60 min under a reaction condition of [Fe(3+)] =0.25 mM, [H(2)O(2)] =10 mM, T=35 °C, and pH=3. LC-MS analysis technique was used to analyze the possible degradation intermediates. The degradation pathways of nalidixic acid were proposed according to the identified intermediates and the electron density distribution of nalidixic acid. The Fenton-like degradation reaction of nalidixic acid mainly begins with the electrophilic attack of hydroxyl radical towards the C3 position which results in the ring-opening reaction; meanwhile, hydroxyl radical attacking to the branched alkyl groups of nalidixic acid leads to the oxidation at the branched alkyl groups.


Asunto(s)
Peróxido de Hidrógeno/metabolismo , Hierro/metabolismo , Ácido Nalidíxico/metabolismo , Cromatografía Liquida , Radical Hidroxilo/metabolismo , Hierro/análisis , Espectrometría de Masas , Metales Pesados/aislamiento & purificación , Metales Pesados/metabolismo , Oxidación-Reducción , Aguas Residuales/química
15.
J Hazard Mater ; 190(1-3): 493-500, 2011 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-21497991

RESUMEN

The Fenton-like degradation of sulfasalazine solution is studied in this work. The effects of reaction parameters such as Fe(3+) concentration, initial H(2)O(2) dosage and the reaction temperature are evaluated. For sulfasalazine of 100mg/L, the removal of sulfasalazine, chemical oxygen demand (COD) and total organic carbon (TOC) reached 99.5%, 84.2% and 41% in 60 min with 0.20mM Fe(3+) and 16 mM H(2)O(2) at 35°C, respectively. The complexed Fe(3+) presents a reaction constant of 0.062 min(-1)mM(-1) while that of free Fe(3+) is 2.526 min(-1)mM(-1) for sulfasalazine degradation. LC-MS technology was used to analysis the possible degradation intermediates. The degradation of sulfasalazine principally begins with the attack of hydroxyl radical on the azo-group as well as the sulfanilamido group. Both intramolecular rearrangement and bimolecular reaction occur simultaneously after the hydroxyl radical attack. Further attack of the active oxidative species results in the cleavage of the aromatic rings and the production of CO(2). The degradation of industrial sulfasalazine wastewater with a COD of 3425 mg/L has also been achieved by Fenton reaction with different dosage of H(2)O(2). Relatively better removal efficiency is observed at moderate Fe/H(2)O(2) molar ratio from 1/5 to 2/5 for industrial sulfasalazine wastewater treatment.


Asunto(s)
Peróxido de Hidrógeno/química , Sulfasalazina/química , Contaminantes Químicos del Agua/química , Antiinfecciosos/química , Carbono/química , Dióxido de Carbono , Cromatografía Líquida de Alta Presión , Residuos Industriales , Cinética , Espectrometría de Masas , Oxígeno/química , Soluciones , Temperatura
16.
Guang Pu Xue Yu Guang Pu Fen Xi ; 25(6): 992-5, 2005 Jun.
Artículo en Chino | MEDLINE | ID: mdl-16201391

RESUMEN

Complexes of chitosan with Cu(II) were prepared by adding Cu(OAc)2.H2O to chitosan solution. IR, UV, elemental analysis, and thermal weight analysis were used to characterize the complex. The results showed that there were coordinate bands formed. H2O2 was used to degrade chitosan-Cu(II) complex, and the molecular distribution of degraded products was investigated. The result suggested that the chitosan could be degraded rapidly, the degradation started from higher molecular weight range, and the molecular weight distribution of oligosaccharides was much more narrow than that of degraded products with usual methods, such as hydrolysis acidic and oxidizing conditions. The index of molecular weight distribution changed with the average degradability. When exceeding 10 oligosaccharides, the smaller the DP, the smaller the index.


Asunto(s)
Quitosano/química , Cobre/química , Oligosacáridos/química , Compuestos Organometálicos/química , Peso Molecular , Compuestos Organometálicos/síntesis química , Oxidación-Reducción , Espectrofotometría Infrarroja , Espectrofotometría Ultravioleta
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